## Archive for July 19, 2011

### Skill-Testing Questions and Captcha

All lotteries have three major components:

- There is a value associated with the prize;
- The organization running the sweepstakes benefits financially; and,
- The winner is chosen at random.

To avoid being an illegal private lottery, at least one of the three components must be removed. Canadian sweepstakes law requires that the third component (winners chosen at random) be removed. That is, the sponsoring organization cannot use pure luck alone to determine who wins. There must be some element of skill involved.

Hence the disclaimer on lotteries open to residents of Canada, such as the following from the Bizrate sweepstakes:

If a Canadian resident wins a prize, that person must also answer correctly within a 5 minute time period a mathematical skill-testing question (STQ)…

Apparently, Canadian courts have determined that a mathematical expression containing at least three binary operators is sufficient to qualify as an STQ. Hence, a person whose name is chosen at random might have to determine the value of the following before being awarded the prize:

8 × 6 – 5 + 9

The expression above is an actual STQ that was used in a Tim Horton’s contest a few years ago. (A woman with a learning disability gave the incorrect answer of 51. When she appealed, she was given a second chance, and they gave her the same question. Again, she answered 51. Amid much protest, Tim Horton’s eventually relented and awarded the prize to the woman anyway, though it’s unclear to me how they got around the STQ requirement.)

Similar STQ’s are now being used as captchas on web sites. I was presented with the following math question when submitting a comment to a site the other day:

I really thought they missed a golden opportunity, though, so I submitted a second comment with the following image attached: